- SPECIAL REPORTS
It’s often said that necessity is the mother of invention. Sometimes, it’s also the mother of a company.
In 1965, Dorner Manufacturing Corp. started out making punched metal lids for cans. As business grew, the Milwaukee-area manufacturer faced a problem: How to efficiently remove the scrap produced when stamping out 16 million lids annually.
Dorner’s engineers came up with a solution: a wide-belt, low-profile conveyor that could fit under the die. The conveyor worked so well the company’s owners decided to get out of the stamping business and focus entirely on refining, manufacturing and marketing their unique, shop-made conveyor.
Some 47 years later, Dorner enjoys more than $40 million in sales annually and produces conveyors for everything from bratwurst and cheddar cheese to plastic cups and hand grenades.
During a recent tour of Dorner’s headquarters and manufacturing facility, I found the entrepreneurial spirit that led to the development of that first conveyor is alive and well. Several production machines were designed and built in-house, including a machine for drilling holes in conveyor rails and a machine for bonding a V-shaped guide strip to the bottom of plastic belt material.
The facility is surprisingly vertically oriented. Keeping a wide range of manufacturing processes in-house shortens turn-around times and gives the company greater control over quality. For example, Dorner roll-forms the bed plates for its conveyors in-house, rather than farm the process out to a job shop. “We do that in-house because it has to be very flat and square,” says Tim Hanson, product manager for Dorner’s sanitary products group. “Even a slight deviation means the conveyor won’t track well.”
Lean manufacturing principles are evident throughout the facility. Every conveyor is built to order. (Turnaround time is three to seven days for an aluminum-based conveyor or seven to 12 days for a stainless steel one.) Virtually everything—parts bins, work orders, tools—is color-coded to prevent errors. Visual work instructions show associates how to process and assemble parts. In the belt-assembly cell, a poster graphically illustrates the cost of wasted material. Cross-training is encouraged, and associates can boost their pay by learning new skills.
The company’s latest offering is the Precision Move package of upgrades for the 2200 and 3200 Series of low-profile belt conveyors. The upgrades were designed for assembly, manufacturing and packaging applications that call for extremely accurate movement of product at specific times, distances and intervals. Applications include robotic pick-and-place, precision indexing, timed conveying, vision inspection and handling of wide parts or sheets.
The Precision Move package includes the timing belt, integrated servomotor and drive, controls and mounting for the gear motor. To keep the belt from slipping under load, ribs on the bottom of the timing belt match up with teeth on the drive sprocket. Equipped with Precision Move components, the 3200 conveyor has an accuracy ±0.2 inch and the 2200 conveyor has an accuracy ±0.4 inch.
The 3200 conveyor can carry a maximum load of 750 pounds. Maximum belt speed is 520 fpm. Belt width ranges from 3.75 to 18 inches, and conveyor length ranges from 2 to 50 feet. Pucks or pallets can be mounted directly on the conveyor belt with an accuracy of ±0.005 inch between them.
The 2200 conveyor can carry a maximum load of 200 pounds. Maximum belt speed is 370 fpm. Belt width ranges from 1.75 to 24 inches, and conveyor length ranges from 1.5 to 30 feet.
To see how Tervis Tumbler uses Dorner conveyors in automated assembly systems, click here.
For more information on Dorner conveyors, call 800-397-8664 or click www.dornerconveyors.com.